7 files changed, 138 insertions, 71 deletions

diff --git a/drivers/hid/hid-3m-pct.c b/drivers/hid/hid-3m-pct.c
index ea475964d05a..4fb7c7528d16 100644
--- a/drivers/hid/hid-3m-pct.c
+++ b/drivers/hid/hid-3m-pct.c
@@ -28,7 +28,6 @@ MODULE_LICENSE("GPL");
 #include "hid-ids.h"
 
 #define MAX_SLOTS               60
-#define MAX_TRKID               USHRT_MAX
 
 /* estimated signal-to-noise ratios */
 #define SN_MOVE                 2048
@@ -36,14 +35,11 @@ MODULE_LICENSE("GPL");
 
 struct mmm_finger {
         __s32 x, y, w, h;
-        __u16 id;
-        bool prev_touch;
         bool touch, valid;
 };
 
 struct mmm_data {
         struct mmm_finger f[MAX_SLOTS];
-        __u16 id;
         __u8 curid;
         __u8 nexp, nreal;
         bool touch, valid;
@@ -117,11 +113,6 @@ static int mmm_input_mapping(struct hid_device *hdev, struct hid_input *hi,
                                         0, 1, 0, 0);
                         return 1;
                 case HID_DG_CONTACTID:
-                        field->logical_maximum = MAX_TRKID;
-                        hid_map_usage(hi, usage, bit, max,
-                                        EV_ABS, ABS_MT_TRACKING_ID);
-                        input_set_abs_params(hi->input, ABS_MT_TRACKING_ID,
-                                             0, MAX_TRKID, 0, 0);
                         input_mt_init_slots(hi->input, MAX_SLOTS);
                         return 1;
                 }
@@ -152,7 +143,6 @@ static int mmm_input_mapped(struct hid_device *hdev, struct hid_input *hi,
  */
 static void mmm_filter_event(struct mmm_data *md, struct input_dev *input)
 {
-        struct mmm_finger *oldest = 0;
         int i;
         for (i = 0; i < MAX_SLOTS; ++i) {
                 struct mmm_finger *f = &md->f[i];
@@ -161,6 +151,7 @@ static void mmm_filter_event(struct mmm_data *md, struct input_dev *input)
                         continue;
                 }
                 input_mt_slot(input, i);
+                input_mt_report_slot_state(input, MT_TOOL_FINGER, f->touch);
                 if (f->touch) {
                         /* this finger is on the screen */
                         int wide = (f->w > f->h);
@@ -168,33 +159,16 @@ static void mmm_filter_event(struct mmm_data *md, struct input_dev *input)
                         int major = max(f->w, f->h) >> 1;
                         int minor = min(f->w, f->h) >> 1;
 
-                        if (!f->prev_touch)
-                                f->id = md->id++;
-                        input_event(input, EV_ABS, ABS_MT_TRACKING_ID, f->id);
                         input_event(input, EV_ABS, ABS_MT_POSITION_X, f->x);
                         input_event(input, EV_ABS, ABS_MT_POSITION_Y, f->y);
                         input_event(input, EV_ABS, ABS_MT_ORIENTATION, wide);
                         input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, major);
                         input_event(input, EV_ABS, ABS_MT_TOUCH_MINOR, minor);
-                        /* touchscreen emulation: pick the oldest contact */
-                        if (!oldest || ((f->id - oldest->id) & (SHRT_MAX + 1)))
-                                oldest = f;
-                } else {
-                        /* this finger took off the screen */
-                        input_event(input, EV_ABS, ABS_MT_TRACKING_ID, -1);
                 }
-                f->prev_touch = f->touch;
                 f->valid = 0;
         }
 
-        /* touchscreen emulation */
-        if (oldest) {
-                input_event(input, EV_KEY, BTN_TOUCH, 1);
-                input_event(input, EV_ABS, ABS_X, oldest->x);
-                input_event(input, EV_ABS, ABS_Y, oldest->y);
-        } else {
-                input_event(input, EV_KEY, BTN_TOUCH, 0);
-        }
+        input_mt_report_pointer_emulation(input, true);
         input_sync(input);
 }
 
diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index f400e47092c4..c48c81f0308d 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -11,17 +11,18 @@
 #include <linux/input/mt.h>
 #include <linux/slab.h>
 
+#define TRKID_SGN       ((TRKID_MAX + 1) >> 1)
+
 /**
  * input_mt_init_slots() - initialize MT input slots
  * @dev: input device supporting MT events and finger tracking
  * @num_slots: number of slots used by the device
  *
  * This function allocates all necessary memory for MT slot handling
- * in the input device, adds ABS_MT_SLOT to the device capabilities
- * and sets up appropriate event buffers. All slots are initially
- * marked as unused by setting ABS_MT_TRACKING_ID to -1. May be called
- * repeatedly. Returns -EINVAL if attempting to reinitialize with a
- * different number of slots.
+ * in the input device, prepares the ABS_MT_SLOT and
+ * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
+ * May be called repeatedly. Returns -EINVAL if attempting to
+ * reinitialize with a different number of slots.
  */
 int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
 {
@@ -38,6 +39,7 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
 
         dev->mtsize = num_slots;
         input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
+        input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
         input_set_events_per_packet(dev, 6 * num_slots);
 
         /* Mark slots as 'unused' */
@@ -61,5 +63,108 @@ void input_mt_destroy_slots(struct input_dev *dev)
         dev->mt = NULL;
         dev->mtsize = 0;
         dev->slot = 0;
+        dev->trkid = 0;
 }
 EXPORT_SYMBOL(input_mt_destroy_slots);
+
+/**
+ * input_mt_report_slot_state() - report contact state
+ * @dev: input device with allocated MT slots
+ * @tool_type: the tool type to use in this slot
+ * @active: true if contact is active, false otherwise
+ *
+ * Reports a contact via ABS_MT_TRACKING_ID, and optionally
+ * ABS_MT_TOOL_TYPE. If active is true and the slot is currently
+ * inactive, or if the tool type is changed, a new tracking id is
+ * assigned to the slot. The tool type is only reported if the
+ * corresponding absbit field is set.
+ */
+void input_mt_report_slot_state(struct input_dev *dev,
+                                unsigned int tool_type, bool active)
+{
+        struct input_mt_slot *mt;
+        int id;
+
+        if (!dev->mt || !active) {
+                input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
+                return;
+        }
+
+        mt = &dev->mt[dev->slot];
+        id = input_mt_get_value(mt, ABS_MT_TRACKING_ID);
+        if (id < 0 || input_mt_get_value(mt, ABS_MT_TOOL_TYPE) != tool_type)
+                id = input_mt_new_trkid(dev);
+
+        input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);
+        input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type);
+}
+EXPORT_SYMBOL(input_mt_report_slot_state);
+
+/**
+ * input_mt_report_finger_count() - report contact count
+ * @dev: input device with allocated MT slots
+ * @count: the number of contacts
+ *
+ * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP,
+ * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP.
+ *
+ * The input core ensures only the KEY events already setup for
+ * this device will produce output.
+ */
+void input_mt_report_finger_count(struct input_dev *dev, int count)
+{
+        input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1);
+        input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2);
+        input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3);
+        input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4);
+}
+EXPORT_SYMBOL(input_mt_report_finger_count);
+
+/**
+ * input_mt_report_pointer_emulation() - common pointer emulation
+ * @dev: input device with allocated MT slots
+ * @use_count: report number of active contacts as finger count
+ *
+ * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and
+ * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true.
+ *
+ * The input core ensures only the KEY and ABS axes already setup for
+ * this device will produce output.
+ */
+void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
+{
+        struct input_mt_slot *oldest = 0;
+        int oldid = dev->trkid;
+        int count = 0;
+        int i;
+
+        for (i = 0; i < dev->mtsize; ++i) {
+                struct input_mt_slot *ps = &dev->mt[i];
+                int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
+
+                if (id < 0)
+                        continue;
+                if ((id - oldid) & TRKID_SGN) {
+                        oldest = ps;
+                        oldid = id;
+                }
+                count++;
+        }
+
+        input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
+        if (use_count)
+                input_mt_report_finger_count(dev, count);
+
+        if (oldest) {
+                int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
+                int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y);
+                int p = input_mt_get_value(oldest, ABS_MT_PRESSURE);
+
+                input_event(dev, EV_ABS, ABS_X, x);
+                input_event(dev, EV_ABS, ABS_Y, y);
+                input_event(dev, EV_ABS, ABS_PRESSURE, p);
+        } else {
+                input_event(dev, EV_ABS, ABS_PRESSURE, 0);
+        }
+}
+EXPORT_SYMBOL(input_mt_report_pointer_emulation);
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index f26e2238f6ca..0b0525486711 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -863,19 +863,21 @@ static int wacom_bpt_touch(struct wacom_wac *wacom)
         struct wacom_features *features = &wacom->features;
         struct input_dev *input = wacom->input;
         unsigned char *data = wacom->data;
-        int sp = 0, sx = 0, sy = 0, count = 0;
         int i;
 
         for (i = 0; i < 2; i++) {
                 int p = data[9 * i + 2];
+                bool touch = p && !wacom->shared->stylus_in_proximity;
+
                 input_mt_slot(input, i);
+                input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
                 /*
                  * Touch events need to be disabled while stylus is
                  * in proximity because user's hand is resting on touchpad
                  * and sending unwanted events.  User expects tablet buttons
                  * to continue working though.
                  */
-                if (p && !wacom->shared->stylus_in_proximity) {
+                if (touch) {
                         int x = get_unaligned_be16(&data[9 * i + 3]) & 0x7ff;
                         int y = get_unaligned_be16(&data[9 * i + 5]) & 0x7ff;
                         if (features->quirks & WACOM_QUIRK_BBTOUCH_LOWRES) {
@@ -885,23 +887,10 @@ static int wacom_bpt_touch(struct wacom_wac *wacom)
                         input_report_abs(input, ABS_MT_PRESSURE, p);
                         input_report_abs(input, ABS_MT_POSITION_X, x);
                         input_report_abs(input, ABS_MT_POSITION_Y, y);
-                        if (wacom->id[i] < 0)
-                                wacom->id[i] = wacom->trk_id++ & MAX_TRACKING_ID;
-                        if (!count++)
-                                sp = p, sx = x, sy = y;
-                } else {
-                        wacom->id[i] = -1;
                 }
-                input_report_abs(input, ABS_MT_TRACKING_ID, wacom->id[i]);
         }
 
-        input_report_key(input, BTN_TOUCH, count > 0);
-        input_report_key(input, BTN_TOOL_FINGER, count == 1);
-        input_report_key(input, BTN_TOOL_DOUBLETAP, count == 2);
-
-        input_report_abs(input, ABS_PRESSURE, sp);
-        input_report_abs(input, ABS_X, sx);
-        input_report_abs(input, ABS_Y, sy);
+        input_mt_report_pointer_emulation(input, true);
 
         input_report_key(input, BTN_LEFT, (data[1] & 0x08) != 0);
         input_report_key(input, BTN_FORWARD, (data[1] & 0x04) != 0);
@@ -1283,8 +1272,6 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
                         input_set_abs_params(input_dev, ABS_MT_PRESSURE,
                                              0, features->pressure_max,
                                              features->pressure_fuzz, 0);
-                        input_set_abs_params(input_dev, ABS_MT_TRACKING_ID, 0,
-                                             MAX_TRACKING_ID, 0, 0);
                 } else if (features->device_type == BTN_TOOL_PEN) {
                         __set_bit(BTN_TOOL_RUBBER, input_dev->keybit);
                         __set_bit(BTN_TOOL_PEN, input_dev->keybit);
diff --git a/drivers/input/tablet/wacom_wac.h b/drivers/input/tablet/wacom_wac.h
index 00ca01541d89..b1310ec9720c 100644
--- a/drivers/input/tablet/wacom_wac.h
+++ b/drivers/input/tablet/wacom_wac.h
@@ -42,9 +42,6 @@
 #define WACOM_QUIRK_MULTI_INPUT         0x0001
 #define WACOM_QUIRK_BBTOUCH_LOWRES      0x0002
 
-/* largest reported tracking id */
-#define MAX_TRACKING_ID                 0xfff
-
 enum {
         PENPARTNER = 0,
         GRAPHIRE,
@@ -100,7 +97,6 @@ struct wacom_wac {
         int id[3];
         __u32 serial[2];
         int last_finger;
-        int trk_id;
         struct wacom_features features;
         struct wacom_shared *shared;
         struct input_dev *input;
diff --git a/drivers/input/touchscreen/wacom_w8001.c b/drivers/input/touchscreen/wacom_w8001.c
index 4a2e8cf4c8ef..2a0bec12d12a 100644
--- a/drivers/input/touchscreen/wacom_w8001.c
+++ b/drivers/input/touchscreen/wacom_w8001.c
@@ -48,8 +48,6 @@ MODULE_LICENSE("GPL");
 #define W8001_PKTLEN_TPCCTL     11      /* control packet */
 #define W8001_PKTLEN_TOUCH2FG   13
 
-#define MAX_TRACKING_ID         0xFF    /* arbitrarily chosen */
-
 struct w8001_coord {
         u8 rdy;
         u8 tsw;
@@ -87,7 +85,6 @@ struct w8001 {
         char phys[32];
         int type;
         unsigned int pktlen;
-        int trkid[2];
 };
 
 static void parse_data(u8 *data, struct w8001_coord *coord)
@@ -116,28 +113,23 @@ static void parse_data(u8 *data, struct w8001_coord *coord)
 
 static void parse_touch(struct w8001 *w8001)
 {
-        static int trkid;
         struct input_dev *dev = w8001->dev;
         unsigned char *data = w8001->data;
         int i;
 
         for (i = 0; i < 2; i++) {
-                input_mt_slot(dev, i);
+                bool touch = data[0] & (1 << i);
 
-                if (data[0] & (1 << i)) {
+                input_mt_slot(dev, i);
+                input_mt_report_slot_state(dev, MT_TOOL_FINGER, touch);
+                if (touch) {
                         int x = (data[6 * i + 1] << 7) | (data[6 * i + 2]);
                         int y = (data[6 * i + 3] << 7) | (data[6 * i + 4]);
                         /* data[5,6] and [11,12] is finger capacity */
 
                         input_report_abs(dev, ABS_MT_POSITION_X, x);
                         input_report_abs(dev, ABS_MT_POSITION_Y, y);
-                        input_report_abs(dev, ABS_MT_TOOL_TYPE, MT_TOOL_FINGER);
-                        if (w8001->trkid[i] < 0)
-                                w8001->trkid[i] = trkid++ & MAX_TRACKING_ID;
-                } else {
-                        w8001->trkid[i] = -1;
                 }
-                input_report_abs(dev, ABS_MT_TRACKING_ID, w8001->trkid[i]);
         }
 
         input_sync(dev);
@@ -319,14 +311,12 @@ static int w8001_setup(struct w8001 *w8001)
                         w8001->pktlen = W8001_PKTLEN_TOUCH2FG;
 
                         input_mt_init_slots(dev, 2);
-                        input_set_abs_params(dev, ABS_MT_TRACKING_ID,
-                                                0, MAX_TRACKING_ID, 0, 0);
                         input_set_abs_params(dev, ABS_MT_POSITION_X,
                                                 0, touch.x, 0, 0);
                         input_set_abs_params(dev, ABS_MT_POSITION_Y,
                                                 0, touch.y, 0, 0);
                         input_set_abs_params(dev, ABS_MT_TOOL_TYPE,
-                                                0, 0, 0, 0);
+                                                0, MT_TOOL_MAX, 0, 0);
                         break;
                 }
         }
@@ -372,7 +362,6 @@ static int w8001_connect(struct serio *serio, struct serio_driver *drv)
         w8001->serio = serio;
         w8001->id = serio->id.id;
         w8001->dev = input_dev;
-        w8001->trkid[0] = w8001->trkid[1] = -1;
         init_completion(&w8001->cmd_done);
         snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
 
diff --git a/include/linux/input.h b/include/linux/input.h
index 99e2a52c0509..6de145df4c1c 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -848,6 +848,7 @@ struct input_keymap_entry {
  */
 #define MT_TOOL_FINGER          0
 #define MT_TOOL_PEN             1
+#define MT_TOOL_MAX             1
 
 /*
  * Values describing the status of a force-feedback effect
@@ -1122,6 +1123,7 @@ struct ff_effect {
  *      of tracked contacts
  * @mtsize: number of MT slots the device uses
  * @slot: MT slot currently being transmitted
+ * @trkid: stores MT tracking ID for the current contact
  * @absinfo: array of &struct absinfo elements holding information
  *      about absolute axes (current value, min, max, flat, fuzz,
  *      resolution)
@@ -1206,6 +1208,7 @@ struct input_dev {
         struct input_mt_slot *mt;
         int mtsize;
         int slot;
+        int trkid;
 
         struct input_absinfo *absinfo;
 
diff --git a/include/linux/input/mt.h b/include/linux/input/mt.h
index d7f6518e3222..b3ac06a4435d 100644
--- a/include/linux/input/mt.h
+++ b/include/linux/input/mt.h
@@ -13,6 +13,8 @@
 
 #include <linux/input.h>
 
+#define TRKID_MAX       0xffff
+
 /**
  * struct input_mt_slot - represents the state of an input MT slot
  * @abs: holds current values of ABS_MT axes for this slot
@@ -36,9 +38,20 @@ static inline int input_mt_get_value(const struct input_mt_slot *slot,
 int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots);
 void input_mt_destroy_slots(struct input_dev *dev);
 
+static inline int input_mt_new_trkid(struct input_dev *dev)
+{
+        return dev->trkid++ & TRKID_MAX;
+}
+
 static inline void input_mt_slot(struct input_dev *dev, int slot)
 {
         input_event(dev, EV_ABS, ABS_MT_SLOT, slot);
 }
 
+void input_mt_report_slot_state(struct input_dev *dev,
+                                unsigned int tool_type, bool active);
+
+void input_mt_report_finger_count(struct input_dev *dev, int count);
+void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count);
+
 #endif